Answer: 2500 units
Explanation: Since government plans on reducing the market equilibrium rent to $1500 per month, it's required of the govt. to extend the provision of apartments by 2500 units.
The equilibrium rent is $2000 and also the equilibrium quantity is 12,500 units. If 2500 more units were added by the govt. this might cause a rise of 15,000 unit available for rent within the market.
The equilibrium price would now be $1500 (the rent the govt. is trying to achiev.) and also the equilibrium quantity 15,000 units